Wednesday, 10 August 2011

The exam season may be over, but here's a simple piece of advice for next semester. Go for a brisk walk before studying and your memory of the material is likely to benefit.

Carlos Salas and his colleagues had dozens of students study 30 nouns, each displayed for 6 seconds. Some of the students went for a ten-minute walk before being presented with the words. They were told to adopt "the walking speed one would use when late to an appointment, but without the anxiety caused by such a scenario". Other students spent the same time sitting quietly looking at pictures of natural landscapes. After the study phase, some of the students went for another ten-minute walk before attempting to recall as many of the words as they could; other students sat quietly for ten minutes before their recall attempt. This meant there were four experimental groups (walk-walk, walk-sit, sit-sit, and sit-walk, depending on how the participants behaved before the study and recall phases).

The key finding is that those students who went for a walk before the study period recalled 25 per cent more words correctly compared with students who sat still before the study period. By contrast, walking versus sitting before the attempt at recall made no difference to the students' performance.

Past research has shown context-dependent effects on memory. For example, if you chew gum while learning, your recall performance will benefit if you also chew gum when attempting to retrieve memories. No evidence for this was found in this study in the sense that the students' performance was no better when their pre-recall activity (walk vs. sit) matched their pre-learning activity, perhaps because the recall test followed too soon after the learning phase, so that the effects of the earlier walk or sitting period were still ongoing.

Another detail of this study is that the researchers asked the students to report their levels of arousal and tension after the periods of sitting or walking. Arousal was higher after walking than sitting, but tension was no different. So increased arousal is a possible physiological mechanism underlying the benefits of a pre-study walk (see earlier Digest item: "Memory performance boosted while walking").

Salas and his team also looked at meta-memory: this is people's insight into their own memory processes. During the study phase, after each word appeared, the participants were asked to indicate their likelihood of recalling it correctly. Students who sat for ten minutes before studying tended to significantly overestimate their later performance. By contrast, the walkers were much more accurate. However, there was no absolute difference in the predictions made by the two groups. In other words, it seems the walkers only had superior meta-memory because walking boosted their performance to match their confidence.

"Overall, these results suggest that individuals can gain a memory advantage from a ten-minute walk before studying," the researchers said. "Given [these] positive results ... and [their] potentially important practical applications, we hope that researchers will continue to explore the relationship between walking, memory, and meta-memory."
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